A microwave network virtualization technology is implemented based on a Software Defined Network (SDN) solution, and with reference to some of a Network Function Virtualization (NFV) technology: Chain network nodes or ring network nodes are simplified as a multiport virtual network element, so as to shrink a network scale and simplify network operation and maintenance. For example, a chain network includes a master (Master) node and multiple Access Point (AP). Before virtualization is performed, the master node and the multiple APs are independent devices. A user side needs to obtain connections between the master node and the multiple APs and information about the master node and the multiple APs. After the master node and the multiple APs are virtualized as a virtual network element, the user side considers the master node and the multiple APs as one network element. From a perspective of the user side, the network scale is reduced, and the user side needs to obtain information about only one virtual network element, so that network operation and maintenance are simplified.
There are two types of services running in the virtual network element: a virtualization service and a non-virtualization service. From a perspective of the user side, there is no difference between a virtualization packet and a non-virtualization packet. However, in the virtual network element, because the two types of services are processed in different manners, the two types of services need to be distinguished. The virtualization packet is a data unit that is used to exchange and transmit the virtualization service in a network, and the non-virtualization packet is a data unit that is used to exchange and transmit the non-virtualization service in the network. The virtualization service is transmitted in the virtual network element, and this may be implemented in the following two manners: (1) Multi-Protocol Label Switching (MPLS) forwarding: a direction from the AP to the Master node is used as an example, and an ingress AP encapsulates a one-layer MPLS label at an outer layer of the virtualization packet after the virtualization packet enters the virtual network element. The ingress AP is the first AP that receives the virtualization packet in the virtual network element. Then, an intermediate AP in the multiple APs forwards the service according to the outer-layer MPLS label, and finally the virtualization packet is sent to the master node. The master node removes the outer-layer MPLS label, and processes the service according to an inner-layer MPLS label of the virtualization packet. (2) QinQ forwarding: a difference between QinQ forwarding and MPLS forwarding is that forwarding is performed by using a two-layer VLAN tag in QinQ forwarding.
A Distributed Switching Architecture (DSA) technology is used in the virtual network element, connection and communication between the master node and the multiple APs are performed in a cascading manner. A port between connected devices needs to be configured as a cascaded port, and a transmitted virtualization packet is marked with a DSA tag. At an interface board of the Master node, the interface board removes the DSA tag, and in this case, when a virtualization packet and a non-virtualization packet simultaneously reach a port of the Master node, the Master cannot distinguish between the virtualization packet and the non-virtualization packet. Because the virtualization packet and the non-virtualization packet are processed in different manners, if the Master node cannot distinguish between the virtualization packet and the non-virtualization packet, a packet is incorrectly processed. For example, the virtualization packet is considered as the non-virtualization packet in processing.